Data type precedence (Transact-SQL)

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APPLIES TO: yesSQL Server yesAzure SQL Database yesAzure Synapse Analytics (SQL DW) yesParallel Data Warehouse

When an operator combines expressions of different data types, the data type with the lower precedence is first converted to the data type with the higher precedence. If the conversion isn't a supported implicit conversion, an error is returned. For an operator combining operand expressions having the same data type, the result of the operation has that data type.

SQL Server uses the following precedence order for data types:

  1. user-defined data types (highest)
  2. sql_variant
  3. xml
  4. datetimeoffset
  5. datetime2
  6. datetime
  7. smalldatetime
  8. date
  9. time
  10. float
  11. real
  12. decimal
  13. money
  14. smallmoney
  15. bigint
  16. int
  17. smallint
  18. tinyint
  19. bit
  20. ntext
  21. text
  22. image
  23. timestamp
  24. uniqueidentifier
  25. nvarchar (including nvarchar(max) )
  26. nchar
  27. varchar (including varchar(max) )
  28. char
  29. varbinary (including varbinary(max) )
  30. binary (lowest)

See also

Data Types (Transact-SQL)
Expressions (Transact-SQL)
CAST and CONVERT (Transact-SQL)